The present invention provides a boat and method for holding one or more substrates during a ball grid array packaging assembly. The boat comprises a base and one or more spring locks. The base has one or more openings which provide access to both faces of said substrates. The base has bottom supports protruding into the openings to retain the substrates from below and top supports protruding into the openings to retain the substrates from above. The spring locks apply lateral pressure to the substrates forcing the substrates over the bottom supports and under the top supports, whereby the boat can be flipped with the substrates retained between the top supports and the bottom supports. In one embodiment, substrates are installed in the boat, and the entire boat is flipped when the opposite face needs to be accessed, rather than manually flipping each substrate.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for assembling ball grid array packages, comprising the steps of: (a) installing one or more substrates into a boat; wherein said boat has one or more openings for retaining said substrates providing access to both faces of said substrates; said boat having bottom supports to retain said substrates from below, top supports to retain said substrates from above, and a means for biasing said substrates against one corner of said openings; (b) attaching dies to said substrates; (c) performing wire bond to form electrical contact between said die and said substrate; (d) encapsulating said die; (e) flipping said boat to provide access to the opposite face of said substrate; (f) marking said substrates; (g) flipping said boat to provide access to the opposite face of said substrate; and (h) attaching solder balls to said substrate.
2. The method of claim 1 wherein said means for biasing said substrate against one corner of said opening is a spring lock wherein the spring applies force to a corner of said substrate through a movable pusher.
3. The method of claim 2 wherein said substrates are installed in said openings by retracting said movable pusher and placing said substrates into said openings between said top supports and resting on said bottom supports; then releasing said movable pusher; whereby said movable pusher applies a force to said substrate, biasing said substrate against the walls of said opening opposite said spring lock.
4. The method of claim 2 wherein the face of said movable pusher in contact with said substrate is at an angle of between about 5 degrees and 45 degrees from vertical.
5. The method of claim 2 wherein the face of said movable pusher in contact with said substrate is at an angle of between about 20 degrees and 40 degrees from vertical.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
August 14, 2000
September 4, 2001
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